Community Forums

Judy Z · 10-07-2015, 10:41 AM

Hi: We have a 2002 Gulf Stream Ultra Class C motor home.

Recently installed a new Marine RV battery, deep cycle. With no electrical draw on the battery (other than propane and other alarm indicators), the charge does not even last a full 24 hours. The truck first has to be started, in order to get the generator going. We run the generator for an hour, at which time the test panel indicates 100% battery. If, however, we hook up to house power to charge the coach, the battery lasts several days.

Any ideas? Does anyone have information as to how long a battery should hold a charge?

/judy

J Birder · 10-07-2015, 10:48 AM

First, an hour is not enough to charge a mostly depleted battery. Four to five hours would be closer.

Second, the marine batteries are not true deep cycle batteries. They are actually a hybrid between starting batteries and deep cycle batteries. Their construction more closely resembles the starting batteries. If you want a true deep cycle battery, get a pair of 6 volt golf cart batteries and hook them in series. There are some 12 volt golf cart batteries, but they tend to be very expensive and very heavy.

Joel

**pasdad1** · 10-07-2015, 11:20 AM

Something else has to be drawing a fair amount of power to drain it in 24 hours. You need a multi-meter capable of measuring DC amps to really know how much load is on the battery. Then you start pulling fuses one-by-one - and when the amp draw drops - you will know which circuit is the culprit.

Do you have a refrigerator that runs on 12vdc ?

Judy Z · 10-07-2015, 01:41 PM

Yes. The refrigerator needs a continuous 12 VDC supply for electronic control to function. (Sorry. I forgot to indicate the refrigerator is running on propane when the battery dies out.) Is this a big enough drain within, say, a 12-hour period?

wa8yxm · 10-07-2015, 02:48 PM

Minimum charge for a battery at 50 percent is six hours. Though a starting battery may be doable in 4.. Your MARINE/deep cycle is a starting battery. not a DEEP CYCLE (Case is important in this post).

Judy Z · 10-08-2015, 09:00 AM

Thanks to all for the information on the battery and the length of time necessary to charge it. I will give it a good long charge before we head out dry camping the end of the month.

Happy trails!

/judy

nothermark · 10-08-2015, 09:15 AM

You are missing another point. Letting the battery run flat also shortens the life. Either put a disconnect on the battery or a float charger and leave it plugged in. Chances are good you have a single stage converter charger that will cook the battery if left on.

What you really need is a 31/2 digit or better voltmeter to read the charge voltage with. You can then estimate the state of charge a lot better than the idiot light panel. You also need to know that it is checked a couple of hours after removing the charging power to see what the battery settles at. There are multiple pages of battery information on the web and in this site. Look for flooded cell lead acid battery.

Judy Z · 10-08-2015, 03:07 PM

The battery compartment has an On--Off switch. I turn it Off while the motor home is in storage for an extended period of time. Otherwise, it is left On, even during travel and hookups at our destination (with or without electrical). Is this wrong? And, yes, our motor home has a converter.

I will do more research on "flooded cell lead acid battery".

Thanks for the informatio.